Heat Exchanger for Vehicle

ABSTRACT

A heat exchanger for a vehicle may include a heat exchanging part including a plurality of introduction holes and discharge holes to introduce and discharge respective working fluids, including a plurality of plates stacked therein to alternately form channels through which the respective working fluids flow, and heat-exchanging the respective working fluids passing through the respective channels with each other, a bypass part forming a bypass channel which is connected to a sub-discharge hole in a sub-introduction hole, sub-discharge holes formed at both sides based on a connection hole formed at one side in one surface of the heat exchanging part, and a valve unit mounted at the connection hole, the sub-introduction hole, and the sub-discharge hole and selectively connecting the connection hole to the sub-introduction hole or the sub-discharge hole.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority to and the benefit of Korean Patent Application No. 10-2014-0076490 filed Jun. 23, 2014, the entire contents of which is incorporated herein for all purposes by this reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a heat exchanger for a vehicle. More particularly, the present invention relates to a heat exchanger for a vehicle that is capable of controlling a temperature by allowing respective working fluids to be introduced therein and flow therein, and selectively heat-exchanging the respective working fluids with each other depending on temperatures of the introduced working fluids.

2. Description of Related Art

Generally, a heat exchanger, which transfers heat from a fluid having a higher temperature to a fluid having a lower temperature through a heat conductive wall, is used in a heater, a cooler, an evaporator, a condenser, or the like.

The heat exchanger reuses heat energy or controls temperatures of introduced working fluids so as to be appropriate for their purpose, is generally used in an air conditioning system, a transmission oil cooler, or the like, of a vehicle, and is mounted in an engine compartment.

When the heat exchanger is mounted in the engine compartment having a limited space, it is difficult to secure a space and mount the heat exchanger. Therefore, research for miniaturization, lightness, efficiency improvement, and function improvement of the heat exchanger has been continuously conducted.

The heat exchanger according to the related art as described above should control temperatures of the respective working fluids depending on a state of the vehicle and then supply the working fluid to an engine, a transmission, or an air conditioning device of the vehicle. However, to this end, separate branch circuits and valves should be installed on channels of the introduced working fluids. Therefore, the numbers of components and assemblers are increased, and a layout becomes complicated.

In addition, when the separate branch circuits and valves are not installed, it is impossible to control a heat exchange amount depending on flow rates of the working fluids, such that it is impossible to efficiently control the temperatures of the working fluids.

The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

BRIEF SUMMARY

Various aspects of the present invention are directed to providing a heat exchanger for a vehicle having advantages of improving fuel efficiency of a vehicle and improving performance of a transmission by controlling temperatures of transmission oil and a coolant through heat exchange between the transmission oil and the coolant while allowing the transmission oil and the coolant to flow therein, and simultaneously performing warming and cooling functions of the transmission oil through a valve unit operated depending on a temperature of the transmission oil at the time of controlling the temperatures.

Various aspects of the present invention are directed to providing a heat exchanger for a vehicle having advantages of decreasing a cost by eliminating valves that are separately installed according to the related art, forming a valve unit operated depending on a temperature of transmission oil integrally with the heat exchanger, and configuring the valve unit so as to be directly mounted in a transmission to simplify a pipe layout and decrease the number of components.

According to various aspects of the present invention a heat exchanger for a vehicle may include a heat exchanging part including a plurality of introduction holes and discharge holes formed in one surface and other surfaces thereof to introduce and discharge respective working fluids, including a plurality of plates stacked therein to alternately form channels through which the respective working fluids flow, and heat-exchanging the respective working fluids passing through the respective channels with each other, a bypass part connected to one of the plurality of introduction holes and protruding from one surface of the heat exchanging part in order to form a bypass channel which is connected to a sub-discharge hole in a sub-introduction hole, sub-discharge holes formed at both sides based on a connection hole formed at one side in one surface of the heat exchanging part and separated from the channels so that the working fluid bypasses the channels, and a valve unit mounted at the connection hole, the sub-introduction hole, and the sub-discharge hole and selectively connecting the connection hole to the sub-introduction hole or the sub-discharge hole using linear displacement that is changed depending on a temperature of the working fluid introduced into the connection hole to introduce the working fluid into the channels or introduce the working fluid to the bypass channel, thereby controlling a flow direction of the working fluid.

The introduction holes may include a first introduction hole formed in one surface of the heat exchanging part and a second introduction hole formed at one side in the other surface of the heat exchanging part, and each of the discharge holes may include a first discharge hole formed in one surface of the heat exchanging part so as to correspond to the first introduction hole and a second discharge hole formed at the other side in the other surface of the heat exchanging part so as to correspond to the second introduction hole.

The first introduction hole and the first discharge hole may be formed at respective edge portions in a diagonal direction in one surface of the heat exchanging part.

The second introduction hole and the second discharge hole may be formed at positions spaced apart from each other, respectively, in a diagonal direction in the other surface of the heat exchanging part, and may be formed so as to face the first introduction hole and the first discharge hole, respectively.

The connection hole may be formed so as to be connected to the second introduction hole in a state in which the connection hole penetrates through the heat exchanging part at a position corresponding to the second introduction hole.

The sub-introduction hole may be connected to one of the channels of the heat exchanging part, and the sub-discharge hole may be connected to the second discharge hole through the bypass channel in a state in which the sub-discharge hole is not connected to the channel.

The working fluids may include a coolant introduced from a radiator and transmission oil introduced from a transmission.

The heat exchanging part may have the other surface mounted at one side of a transmission, may circulate coolant through the first introduction hole and the first discharge hole, and may circulate transmission oil through the second introduction hole and the second discharge hole.

The respective channels may include first channels connected to the first introduction hole and the first discharge hole within the heat exchanging part and having coolant introduced therein through the first introduction hole and moved therein, and second channels formed between the first channels so as to intersect with the first channels, connected to the second introduction hole and the second discharge hole within the heat exchanging part, and having transmission oil introduced therein through the second introduction hole and moved therein.

The heat exchanging part may allow the respective working fluids to flow in opposite directions to each other to heat-exchange the working fluids with each other.

The valve unit may include a housing having one end that is opened and having a first connection port, a second connection port, and a third connection port formed at one side thereof in a length direction, the first connection port being connected to the connection hole, the second connection port being connected to the sub-introduction hole, the third connection port being connected to the sub-discharge hole, and the second and third connection ports being formed at both sides based on the first connection port, respectively, a fixing cap mounted at one end of the housing that is opened to close an inner portion of the housing, a fixing rod having one end fixed to the fixing cap within the housing, a deforming member inserted into the other end of the fixing rod and moving forward or backward on the fixing rod while being expanded or contracted therein depending on a temperature change of the working fluid in a state in which the deforming member is inserted so as to be slidable in the length direction within the housing, and an elastic member interposed between the other end of the housing that is closed and the deforming member and providing elastic force to the deforming member while being compressed at the time of rising depending on the expansion of the deforming member.

The housing may be formed in a cylindrical shape in which one end thereof is opened.

The fixing cap may have a mounting part formed integrally therewith at a center of one surface thereof facing the inner portion of the housing, the mounting part having the fixing rod mounted therein.

The housing may have a ring groove formed along a circumference of an inner peripheral surface of one end thereof that is opened in order to mount a fixing ring fixing the fixing cap.

The deforming member may be made of a wax material that is contracted and expanded therein depending on the temperature of the working material, and may be inserted into the housing in a state in which an outer peripheral surface thereof contacts an inner peripheral surface of the housing.

The elastic member may be formed of a coil spring having one end supported by an inner surface of the other end of the housing that is closed and the other end supported by the deforming member.

It is understood that the term “vehicle” or “vehicular” or other similar terms as used herein is inclusive of motor vehicles in general such as passenger automobiles including sports utility vehicles (SUV), buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft, and the like, and includes hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other alternative fuel vehicles (e.g., fuel derived from resources other than petroleum). As referred to herein, a hybrid vehicle is a vehicle that has two or more sources of power, for example, both gasoline-powered and electric-powered vehicles.

The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description, which together serve to explain certain principles of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a vehicle cooling system using an exemplary heat exchanger for a vehicle according to the present invention.

FIG. 2 is a perspective view of the exemplary heat exchanger for a vehicle according to the present invention.

FIG. 3 is a plan view of the exemplary heat exchanger for a vehicle according to the present invention.

FIG. 4 is a rear view of the exemplary heat exchanger for a vehicle according to the present invention.

FIG. 5 is an exploded perspective view of the exemplary heat exchanger for a vehicle according to the present invention.

FIG. 6 is a cross-sectional view taken along line A-A of FIG. 3.

FIG. 7A and FIG. 7B are cross-sectional views taken along line B-B of FIG. 3.

FIG. 8 is a cross-sectional view taken along line C-C of FIG. 3.

FIG. 9 is an exploded perspective view of a valve unit used in the exemplary heat exchanger for a vehicle according to the present invention.

FIG. 10A and FIG. 10B are diagrams showing an operation state of the valve unit in the exemplary heat exchanger for a vehicle according to an exemplary embodiment of the present invention.

FIG. 11, FIG. 12A, FIG. 12B and FIG. 13 are diagrams showing operation states of the exemplary heat exchanger for a vehicle according to the present invention in each step.

It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and use environment.

DETAILED DESCRIPTION

Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that the present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims.

Referring to the drawings, the heat exchanger 100 for a vehicle according to various embodiments of the present invention is used in a vehicle cooling system in order to cool or warm transmission oil of the vehicle.

The above-mentioned vehicle cooling system is connected through a coolant pipe so that a coolant cooled while passing through a radiator 20 mounted with a cooling fan 21 via a water pump 11 cools an engine 10, and a heater core 30 connected to a vehicle heating system is disposed on the coolant pipe, as shown in FIG. 1.

Here, the heat exchanger 100 for a vehicle according to various embodiments of the present invention controls temperatures of transmission oil and a coolant through heat exchange between the transmission oil and the coolant while allowing the transmission oil and the coolant to flow therein, and simultaneously performs warming and cooling functions of the transmission oil through a valve unit 130 operated depending on a temperature of the transmission oil at the time of controlling the temperatures, thereby making it possible to improve fuel efficiency of the vehicle and improve performance of the transmission 40.

In addition, valves that are separately installed according to the related art are removed, and the valve unit 130 operated depending on the temperature of the transmission oil is formed integrally with the heat exchanger and is configured so as to be directly mounted in the transmission 40 to simplify a pipe layout and decrease the number of components, thereby making it possible to decrease a cost.

That is, in various embodiments, the respective working fluids are configured of the coolant introduced from the radiator 20 and the transmission oil introduced from the transmission 40, and the coolant and the transmission oil are heat-exchanged with each other through the heat exchanger 100 to control the temperature of the transmission oil.

To this end, the heat exchanger 100 for a vehicle according to various embodiments of the present invention is connected between the water pump 11 and the heater core 30 through the coolant pipe, and is mounted integrally with the transmission 40 at one side of the transmission 40 and is connected to the transmission 40 so that the coolant is circulated and the transmission oil is supplied.

The heat exchanger 100 is mainly configured to include a heat exchanging part 110, a bypass part 120, and the valve unit 130, as shown in FIG. 2, FIG. 3, FIG. 4 and FIG. 5. These components will be described in more detail below.

First, the heat exchanging part 110 includes a plurality of introduction holes 116 and discharge holes 118 formed in one surface and other surfaces thereof to introduce and discharge the coolant and the transmission oil, which are the respective working fluids, and a plurality of plates 112 stacked therein to form different channels 114 therein so as to intersect with each other, and heat-exchanges the transmission oil and the coolant passing through the respective channels 114 with each other.

The transmission oil and the coolant are heat-exchanged with each other in the heat exchanging part 110 while passing through the respective channels 114, and at least one introduction hole 116 and one discharge hole 118 are formed in one surface and the other surface of the heat exchanging part 110, respectively, and are connected to the channels 114, respectively.

Here, the heat exchanging part 110 is configured so that engine oil and the transmission oil flow in an opposite direction to the coolant therein in order for the coolant to be heat-exchanged with the engine oil and the transmission oil by a counter flow.

The heat exchanging part 100 configured as described above may be formed in a plate shape in which the plurality of plates 112 are stacked.

In various embodiments, in the bypass part 120, one of the plurality of introduction holes 116 is connected to a connection hole 115 formed at one side of one surface of the heat exchanging part 110.

A sub-introduction hole 117 and a sub-discharge hole 119 are formed at both sides of the connection hole 115, respectively, and the bypass part 120 protrudes from one surface of the heat exchanging part 110 in order to form a bypass channel 122 which is connected to the sub-discharge hole 119 and is separated from the respective channels 114 such that the working fluid bypasses the channels 114.

Here, the bypass channel 122 is in communication with the outside of the heat exchanger 100 through one of the discharge holes 118 without being in communication with the channels 114 formed in the heat exchanging part 110.

Meanwhile, in various embodiments, each of the introduction holes 116 includes a first introduction hole 116 a formed in one surface of the heat exchanging part 110 and a second introduction hole 116 b formed at one side in the other surface of the heat exchanging part 110.

Each of the discharge holes 118 may include a first discharge hole 118 a formed in one surface of the heat exchanging part 110 so as to correspond to the first introduction hole 116 a and a second discharge hole 118 b formed at the other side in the other surface of the heat exchanging part 110 so as to correspond to the second introduction hole 116 b.

The first and second introduction holes 116 a and 116 b are connected to the first and second discharge holes 118 a and 118 b, respectively, through the respective channels 114 within the heat exchanging part 110.

Here, the first introduction hole 116 a and the first discharge hole 118 a are formed at the respective edge portions in a diagonal direction in one surface of the heat exchanging part 110.

In addition, the second introduction hole 116 b and the second discharge hole 118 b are formed at positions spaced apart from each other, respectively, in the diagonal direction in the other surface of the heat exchanging part 110, and are formed so as to face the first introduction hole 116 a and the first discharge hole 118 a, respectively.

In addition, the connection hole 115 may be formed so as to be connected to the second introduction hole 116 b in a state in which it penetrates through the heat exchanging part 110 at a position corresponding to the second introduction hole 116 b.

In addition, the sub-introduction hole 117 may be connected to one of the channels 114 of the heat exchanging part 110, and the sub-discharge hole 119 may be connected to the second discharge hole 118 b through the bypass channel 122 in a state in which it is not connected to the channel 114.

The heat exchanging part 110 configured as described above has the other surface mounted at one side of the transmission 40, circulates the coolant through the first introduction hole 116 a and the first discharge hole 118 a, and circulates the transmission oil through the second introduction hole 116 b and the second discharge hole 118 b.

Meanwhile, the first introduction hole 116 a and the first discharge hole 118 a may be mounted with connection pipes P and be connected to the radiator 20 through connection hoses, or the like, mounted at the connection pipes P.

In various embodiments, each of the channels 114 includes first and second channels 114 a and 114 b, as shown in FIG. 6, FIG. 7A, FIG. 7B and FIG. 8.

First, the first channels 114 a are connected to the first introduction hole 116 a and the first discharge hole 118 a within the heat exchanging part 110, and have the coolant introduced therein through the first introduction hole 116 a and moved therein.

In addition, the second channels 114 b are formed between the first channels 114 a so as to intersect with the first channels 114 a, are connected to the second introduction hole 116 b and the second discharge hole 118 b within the heat exchanging part 110, and have the transmission oil introduced therein through the second introduction hole 116 b and moved therein.

In the case in which the transmission oil is introduced, the sub-introduction hole 117 moves the transmission oil introduced through the connection hole 115 into the edge portion of the heat exchanging part 110 neighboring the first discharge hole 118 a to pass the transmission oil through the respective second channels 114 b.

The transmission oil passing through the respective second channels 114 b passes through the edge portion of the heat exchanging part 110 neighboring the first introduction hole 116 a positioned in the diagonal direction with respect to the edge portion of the heat exchanging part 110 neighboring the first discharge hole 118 a, and is then discharged to the outside of the heat exchanger 100 through the second discharge hole 118 b.

That is, the transmission oil introduced through the connection hole 115 flows in the diagonal direction of the heat exchanging part 110, which is an opposite direction to a flow of the coolant through the respective second channels 114 b via the sub-introduction hole 117. In this case, the transmission oil is heat-exchanged with coolant flowing via the first introduction hole 116 a, the first channels 114 a, and the first discharge hole 118 a.

To the contrary, in the case in which the transmission oil introduced through the connection hole 115 is bypassed without passing through the second channels 114 b, the transmission oil flows to the bypass channel 122 through the sub-discharge hole 119, and is discharged to the outside through the second discharge hole 118 b in a state in which it does not pass through an inner portion of the heat exchanging part 110.

Meanwhile, although the case in which the coolant introduced and discharged through the first introduction hole 116 a and the first discharge hole 118 a flows to the first channels 114 a and the transmission oil is introduced into the connection hole 115 through the second introduction hole 116 b and is then discharged from the sub-introduction hole 117 to the second discharge hole 118 b through the second channels 114 b through a selective operation of the valve unit 130, or passes through the bypass channel 122 from the sub-discharge hole 119 and is then discharged to the second discharge hole 118 b, has been described by way of example in various embodiments, the present invention is not limited thereto. That is, flow directions of the coolant and the transmission oil may be changed with each other.

In addition, although the case in which the valve unit 130 is operated depending on the temperature of the transmission oil has been described by way of example in various embodiments, the present invention is not limited thereto. That is, the valve unit 130 may also be operated depending on the temperature of the coolant.

In addition, the valve unit 130 is mounted at the connection hole 115, the sub-introduction hole 117, and the sub-discharge hole 119 on one surface of the heat exchanging part 110.

The valve unit 130 selectively connects the connection hole 115 to the sub-introduction hole 117 or the sub-discharge hole 119 using linear displacement that is changed depending on the temperature of the transmission oil, which is the working fluid introduced into the connection hole 115, to introduce the transmission oil into the second channels 114 b, thereby passing the transmission oil through the heat exchanging part 110 or bypassing the transmission oil to the bypass channel 122, thereby controlling a flow direction of the transmission oil.

Here, the valve unit 130 includes a housing 132, a fixing cap 134, a fixing rod 136, a deforming member 138, and an elastic member 139, as shown in FIG. 9, which will be described in more detail below.

First, the housing 132 has one end that is opened and has a first connection port 132 a, a second connection port 132 b, and a third connection port 132 c formed at one side thereof in a length direction, wherein the first connection port 132 a is connected to the connection hole 115, the second connection port 132 b is connected to the sub-introduction hole 117, the third connection port 132 c is connected to the sub-discharge hole 119, and the second and third connection ports 132 b and 132 c are formed at both sides based on the first connection port 132 a, respectively.

The housing 132 may be formed in a cylindrical shape in which one end thereof is opened in the length direction.

In various embodiments, the fixing cap 134 is mounted at one end of the housing 132 that is opened to close an inner portion of the housing 132.

Here, the housing 132 may have a ring groove 133 formed along a circumference of an inner peripheral surface of one end thereof that is opened in order to mount a fixing ring 135 fixing the fixing cap 134 inserted into one end thereof that is opened.

That is, separation of the fixing cap 134 inserted into one end of the housing 132 that is opened from the housing 132 may be prevented by the fixing ring 135 mounted in the ring groove 133, and an outer peripheral surface of the fixing cap 134 may be made of rubber in order to prevent the transmission oil introduced into the housing 132 from leaking to the outside between the housing 132 and the fixing cap 134.

The fixing rod 136 has one end fixed to the fixing cap 134 in a state in which it is disposed horizontally in the length direction within the housing 132.

Here, the fixing cap 134 may have a mounting part 134 a formed integrally therewith at the center of one surface thereof facing the inner portion of the housing 132, wherein the mounting part 134 a has the fixing rod 136 mounted therein. In addition, the fixing rod 136 is fixed to the fixing cap 134 in a state in which one end thereof is partially inserted into the mounting part 134 a.

In various embodiments, the deforming member 138 is inserted into the other end of the fixing rod 136 and moves forward or backward on the fixing rod 134 while being expanded or contracted therein depending on a temperature change of the transmission oil introduced into the housing 132 in a state in which it is inserted so as to be slidable in the length direction within the housing 132.

That is, as the deforming member 138 moves forward or backward on the fixing rod 134, a position of the deforming member is varied within the housing 132 while linear displacement of the deforming member is generated.

In addition, the elastic member 139 is interposed between the other end of the housing 132 that is closed and the deforming member 138 and provides elastic force to the deforming member 138 while being compressed at the time of rising depending on the expansion of the deforming member 138.

Here, the elastic member 139 may be formed of a coil spring having one end supported by an inner surface of the other end of the housing 132 that is closed and the other end supported by the deforming member 138.

In the valve unit 130 configured as described above, the deforming member 138 may be made of a wax material that is contracted and expanded therein depending on the temperature of the working fluid and is inserted into the housing 132 in a state in which an outer peripheral surface thereof contacts an inner peripheral surface of the housing 132.

Here, the wax material, which has a volume that is expanded or contracted depending on a temperature, is a material having a property that the volume thereof is expanded therein when the temperature rises and contracts therein by the elastic force of the elastic member 139 to return to an initial volume when the temperature drops.

That is, the deforming member 138 is configured of an assembly including the wax material therein, may move forward or backward on the fixing rod 136 without a change in an appearance in the case in which volume deformation is generated in the wax material depending on the temperature, and more rapidly return to an initial position by the elastic force of the elastic member 139 at the time of moving backward.

An operation of the valve unit 130 configured as described above will be described below with reference to FIG. 10A and FIG. 10B.

FIG. 10A and FIG. 10B are diagrams showing an operation state of the valve unit in the heat exchanger for a vehicle according to various embodiments of the present invention.

First, the deforming member 138 is positioned at the time of being initially mounted so that the first and third connection ports 132 a and 132 c are connected to the connection hole 115 and the sub-discharge hole 119, respectively, as shown in (S1) of FIG. 10A.

In this state, in the case in which a temperature of the transmission oil introduced into the housing 132 through the first connection port 132 a is a predetermined temperature or more, as shown in (S2) of FIG. 10B, the deforming member 138 is expanded to move forward on the fixing rod 136, thereby connecting the first and second connection ports 132 a and 132 b to each other so that the connection hole 115 is connected to the sub-introduction hole 117.

Therefore, the transmission oil is introduced into the housing 132 through the first connection port 132 a, is introduced into the sub-introduction hole 117 connected to the second connection port 132 b, and is then introduced into the respective second channels 114 b formed in the heat exchanging part 110.

In addition, in a state in which the deforming member 138 is expanded, in the case in which a temperature of the transmission oil introduced into the first connection port 132 a through the connection hole 115 is a predetermined temperature or less, the deforming member 138 more rapidly moves backward on the fixing rod 136 by the elastic force of the elastic member 139 while being again contracted.

Therefore, a position of the deforming member 138 again returns to an initial state to connect the first and third connection ports 132 a and 132 c to each other, thereby discharging the introduced transmission oil to the bypass channel 122 through the sub-discharge hole 119 connected to the third connection port 132 c.

Meanwhile, in the case in which the transmission oil having a temperature of less than or equal to the predetermined temperature is introduced in an initial state in which the deforming member 138 is mounted on the fixing rod 136, the expansion or contraction is not generated in the deforming member 138, such that the position of the deforming member 138 is not varied.

Hereinafter, an operation and an action of the heat exchanger 100 for a vehicle according to various embodiments of the present invention configured as described above will be described in detail.

FIGS. 11 to 13 are diagrams showing operation states of the heat exchanger for a vehicle according to various embodiments of the present invention in each step.

First, the transmission oil discharged from the transmission 40 is introduced from the second introduction hole 116 b of the heat exchanger 110 mounted at one side of the transmission 40 into the connection hole 115, and is then introduced into the housing 132 through the first connection port 132 a.

Here, in the case in which a temperature of the transmission oil introduced into the housing 132 is lower than a predetermined temperature, the deforming member 138 of the valve unit 130 is maintained in the initial state without being deformed, as shown in FIG. 11, since the temperature of the transmission oil introduced into the housing 132 is lower than a temperature at which the deformation is generated in the deforming member.

Therefore, the deforming member 138 maintains a state in which it connects the first and third connection ports 132 a and 132 c to each other in a state in which it prevents the transmission oil from being introduced into the second connection port 132 b within the housing 132 (see (S1) of FIG. 10A).

In this case, the transmission oil introduced into the housing 132 of the valve unit 130 is discharged to the sub-discharge hole 119 through the third connection port 135 c, flows along the bypass channel 122 formed in the bypass part 120, is discharged from the heat exchanger 100 through the second discharge hole 118 b without passing through the respective second channels 114 b, and is then introduced again into the transmission 40.

Therefore, introduction of the transmission oil to the second channel 114 b is prevented, and heat exchange between the transmission oil and the coolant that passes through the respective first channels 114 a of the heat exchanging part 110 and is in a low temperature state is prevented.

That is, in the heat exchanger 110 according to various embodiments, in the case in which a rapid warm-up of the transmission oil is required depending on a state or a driving mode of the vehicle, such as a driving state, an idle mode, or an initial start of the vehicle, the bypass channel 122 prevents the transmission oil from being introduced into the respective second channels 114 b positioned between the respective first channels 114 a to prevent the temperature of the transmission oil from being decreased through the heat exchange between the transmission oil and the coolant that passes through the first channels 114 a and is in the low temperature state.

To the contrary, in the case in which the temperature of the transmission oil is higher than the predetermined temperature, that is, in the case in which the transmission oil needs to be cooled, as shown in FIG. 12A and FIG. 12B, the deforming member 138 of the valve unit 130 is expanded therein by the transmission oil that is introduced into the connection hole 115 and is in a high temperature state and moves forward on the fixing rod 136 to move toward the third introduction port 132 c (see (S2) of FIG. 10).

In this case, the deforming member 138 is positioned between the first and third introduction ports 132 a and 132 c within the housing 132 to release connection between the first and third introduction ports 132 a and 132 c to connect the first and second introduction ports 132 a and 132 b to each other.

Therefore, the transmission oil that is discharged from the transmission 40 and is in the high temperature state is introduced into the housing 132 of the valve unit 130 through the connection hole 115 and the first introduction port 132 a via the second introduction hole 116 b.

Then, the transmission oil is introduced into the sub-introduction hole 117 through the second introduction port 132 b opened through generation of linear displacement by the expansion of the deforming member 138, and then flows in the respective second channels 114 b of the heat exchanging part 110.

In this case, the transmission oil that passes through the respective second channels 114 b and is in the high temperature state is introduced into the first introduction hole 116 a and is then heat-exchanged with the coolant passing through the respective first channels 114 a within the heat exchanging part 110, such that the temperature of the transmission oil is controlled.

Here, the coolant and the transmission oil flow in opposite directions to each other along the diagonal direction of the heat exchanging part 110, such that they may be more efficiently heat-exchanged with each other.

Meanwhile, as shown in FIG. 13, the coolant is introduced from the radiator 20 through the first introduction hole 116 a formed in one surface of the heat exchanging part 110, passes through the respective first channels 114 a, and is then discharged through the first discharge hole 118 a, such that it is heat-exchanged with the transmission oil selectively passing through the second channels 114 b by the valve unit 130 operated depending on the temperature of the transmission oil.

Therefore, the transmission oil that needs to be cooled since heat is generated due to fluid friction generated by a torque converter and internal gears is supplied to the transmission 40 in a state in which it is cooled through the heat-exchange with the coolant in the low temperature state within the heat exchanging part 110.

That is, the heat exchanger 100 supplies the cooled transmission oil to the transmission 40 that is rotated at a high speed to prevent generation of slip in the transmission 40.

As described above, in the heat exchanger 100 for a vehicle according to various embodiments of the present invention, when the deforming member 138 of the valve unit 130 is expanded or contracted depending on the temperature of the introduced transmission oil, the deforming member 138 moves forward or backward on the fixing rod 136 to generate the linear displacement, thereby connecting the first connection port 132 a into which the transmission oil is introduced to the second connection port 132 b or the third connection port 132 c within the housing 132 to control the flow of the transmission oil.

In this case, the transmission oil introduced into the housing 132 of the valve unit 130 is again discharged to the transmission 40 via the bypass channel 122 without heat-exchanging with the coolant passing through the first channels 114 a or is heat-exchanged with the coolant that passes through the first channels 114 a and is in the low temperature state while passing through the respective second channels 114 b and is then discharged to the transmission 40 in a state in which it is cooled.

Therefore, when the heat exchanger 100 for a vehicle according to various embodiments of the present invention is used, the heat exchanger 100 for a vehicle controls the temperatures of the transmission oil and the coolant through the heat exchange between the transmission oil and the coolant while allowing the transmission oil and the coolant to flow therein and simultaneously performs the warming and cooling functions of the transmission oil through the valve unit 130 operated depending on the temperature of the transmission oil at the time of controlling the temperature of the transmission oil, thereby making it possible to efficiently control the temperature of the transmission oil depending on the driving state of the vehicle.

In addition, the temperature of the transmission oil may be controlled depending on the driving state of the vehicle, thereby making it possible to improve the fuel efficiency of the vehicle and the performance of the transmission 40.

Further, the warm-up function for decreasing friction at the time of a cold start of the transmission oil and the cooling function for preventing the slip and maintaining durability at the time of driving may be simultaneously performed, thereby making it possible to improve the fuel efficiency and durability of the transmission 40.

Further, the valves that are separately installed according to the related art are removed, and the valve unit 130 operated depending on the temperature of the transmission oil is formed integrally with the heat exchanger 100 and is configured so as to be directly mounted in the transmission 40 to simplify the pipe layout and decrease the number of components, thereby making it possible to decrease a cost and a weight and solve a difficulty in securing a mounting space within an engine compartment.

Further, response characteristics of valve opening and closing operations depending on the temperature of the working fluid are improved, thereby making it possible to more efficiently control the working fluid and improve entire marketability of the vehicle.

Meanwhile, although the case in which the working fluids are configured of the coolant and the transmission oil has been described by way of example in describing the heat exchanger 100 for a vehicle according to various embodiments of the present invention, the present invention is not limited thereto. That is, all of working fluids that need to be cooled or heated through the heat exchange may be used as the working fluids.

In addition, although the case in which the plurality of plates 112 are simply stacked and configured in the accompanying drawings has been described by way of example in describing the heat exchanger 100 for a vehicle according to various embodiments of the present invention, the present invention is not limited thereto. That is, a cover, a bracket, and the like for preventing damage to the heat exchanger due to contact with the other components or fixing the heat exchanger to the other components or into the engine compartment may be mounted on one surface and the other surface of the heat exchanger in consideration of mounting of the heat exchanger.

For convenience in explanation and accurate definition in the appended claims, the terms “upper”, “lower”, “inner” and “outer” are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures.

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents. 

What is claimed is:
 1. A heat exchanger for a vehicle, comprising: a heat exchanging part including a plurality of introduction holes and discharge holes formed in one surface and other surfaces thereof to introduce and discharge respective working fluids, including a plurality of plates stacked therein to alternately form channels through which the respective working fluids flow, and heat-exchanging the respective working fluids passing through the respective channels with each other; a bypass part connected to one of the plurality of introduction holes and protruding from one surface of the heat exchanging part in order to form a bypass channel which is connected to a sub-discharge hole in a sub-introduction hole, sub-discharge holes formed at both sides based on a connection hole formed at one side in one surface of the heat exchanging part and separated from the channels so that the working fluid bypasses the channels; and a valve unit mounted at the connection hole, the sub-introduction hole, and the sub-discharge hole and selectively connecting the connection hole to the sub-introduction hole or the sub-discharge hole using linear displacement that is changed depending on a temperature of the working fluid introduced into the connection hole to introduce the working fluid into the channels or introduce the working fluid to the bypass channel, thereby controlling a flow direction of the working fluid.
 2. The heat exchanger for a vehicle of claim 1, wherein the introduction holes include a first introduction hole formed in one surface of the heat exchanging part and a second introduction hole formed at one side in the other surface of the heat exchanging part, and each of the discharge holes includes a first discharge hole formed in one surface of the heat exchanging part so as to correspond to the first introduction hole and a second discharge hole formed at the other side in the other surface of the heat exchanging part so as to correspond to the second introduction hole.
 3. The heat exchanger for a vehicle of claim 2, wherein the first introduction hole and the first discharge hole are formed at respective edge portions in a diagonal direction in one surface of the heat exchanging part.
 4. The heat exchanger for a vehicle of claim 2, wherein the second introduction hole and the second discharge hole are formed at positions spaced apart from each other, respectively, in a diagonal direction in the other surface of the heat exchanging part, and are formed so as to face the first introduction hole and the first discharge hole, respectively.
 5. The heat exchanger for a vehicle of claim 2, wherein the connection hole is formed so as to be connected to the second introduction hole in a state in which the connection hole penetrates through the heat exchanging part at a position corresponding to the second introduction hole.
 6. The heat exchanger for a vehicle of claim 2, wherein the sub-introduction hole is connected to one of the channels of the heat exchanging part, and the sub-discharge hole is connected to the second discharge hole through the bypass channel in a state in which the sub-discharge hole is not connected to the channel.
 7. The heat exchanger for a vehicle of claim 2, wherein the working fluids include a coolant introduced from a radiator and transmission oil introduced from a transmission.
 8. The heat exchanger for a vehicle of claim 2, wherein the heat exchanging part has the other surface mounted at one side of a transmission, circulates coolant through the first introduction hole and the first discharge hole, and circulates transmission oil through the second introduction hole and the second discharge hole.
 9. The heat exchanger for a vehicle of claim 2, wherein the respective channels include: first channels connected to the first introduction hole and the first discharge hole within the heat exchanging part and having coolant introduced therein through the first introduction hole and moved therein; and second channels formed between the first channels so as to intersect with the first channels, connected to the second introduction hole and the second discharge hole within the heat exchanging part, and having transmission oil introduced therein through the second introduction hole and moved therein.
 10. The heat exchanger for a vehicle of claim 1, wherein the heat exchanging part allows the respective working fluids to flow in opposite directions to each other to heat-exchange the working fluids with each other.
 11. The heat exchanger for a vehicle of claim 1, wherein the valve unit includes: a housing having one end that is opened and having a first connection port, a second connection port, and a third connection port formed at one side thereof in a length direction, the first connection port being connected to the connection hole, the second connection port being connected to the sub-introduction hole, the third connection port being connected to the sub-discharge hole, and the second and third connection ports being formed at both sides based on the first connection port, respectively; a fixing cap mounted at one end of the housing that is opened to close an inner portion of the housing; a fixing rod having one end fixed to the fixing cap within the housing; a deforming member inserted into the other end of the fixing rod and moving forward or backward on the fixing rod while being expanded or contracted therein depending on a temperature change of the working fluid in a state in which the deforming member is inserted so as to be slidable in the length direction within the housing; and an elastic member interposed between the other end of the housing that is closed and the deforming member, and providing elastic force to the deforming member while being compressed at the time of rising depending on the expansion of the deforming member.
 12. The heat exchanger for a vehicle of claim 11, wherein the housing is formed in a cylindrical shape in which one end thereof is opened.
 13. The heat exchanger for a vehicle of claim 11, wherein the fixing cap has a mounting part formed integrally therewith at a center of one surface thereof facing the inner portion of the housing, the mounting part having the fixing rod mounted therein.
 14. The heat exchanger for a vehicle of claim 11, wherein the housing has a ring groove formed along a circumference of an inner peripheral surface of one end thereof that is opened in order to mount a fixing ring fixing the fixing cap.
 15. The heat exchanger for a vehicle of claim 11, wherein the deforming member is made of a wax material that is contracted and expanded therein depending on the temperature of the working material, and is inserted into the housing in a state in which an outer peripheral surface thereof contacts an inner peripheral surface of the housing.
 16. The heat exchanger for a vehicle of claim 11, wherein the elastic member is formed of a coil spring having one end supported by an inner surface of the other end of the housing that is closed and the other end supported by the deforming member. 